string-ext.c: fix memory leak in `tr_parse_pattern`.

mrbgems/mruby-string-ext/src/string.c

@@ -288,7 +288,7 @@ tr_free_pattern(mrb_state *mrb, struct tr_pattern *pat)
 }
 
 static struct tr_pattern*
-tr_parse_pattern(mrb_state *mrb, struct tr_pattern *ret, const mrb_value v_pattern, mrb_bool flag_reverse_enable)
+tr_parse_pattern(mrb_state *mrb, struct tr_pattern *ret, const mrb_value v_pattern, mrb_bool flag_reverse_enable, struct tr_pattern *pat0)
 {
   const char *pattern = RSTRING_PTR(v_pattern);
   mrb_int pattern_length = RSTRING_LEN(v_pattern);
@@ -308,6 +308,7 @@ tr_parse_pattern(mrb_state *mrb, struct tr_pattern *ret, const mrb_value v_patte
            ? ret
            : (struct tr_pattern*)mrb_malloc_simple(mrb, sizeof(struct tr_pattern));
     if (pat1 == NULL) {
+      if (pat0) tr_free_pattern(mrb, pat0);
       tr_free_pattern(mrb, ret);
       mrb_exc_raise(mrb, mrb_obj_value(mrb->nomem_err));
       return NULL;            /* not reached */
@@ -335,6 +336,7 @@ tr_parse_pattern(mrb_state *mrb, struct tr_pattern *ret, const mrb_value v_patte
 
       len = i - start_pos;
       if (len > UINT16_MAX) {
+        if (pat0) tr_free_pattern(mrb, pat0);
         tr_free_pattern(mrb, ret);
         if (ret != pat1) mrb_free(mrb, pat1);
         mrb_raise(mrb, E_ARGUMENT_ERROR, "tr pattern too long (max 65535)");
@@ -482,18 +484,17 @@ static mrb_bool
 str_tr(mrb_state *mrb, mrb_value str, mrb_value p1, mrb_value p2, mrb_bool squeeze)
 {
   struct tr_pattern pat = STATIC_TR_PATTERN;
-  struct tr_pattern rep_storage = STATIC_TR_PATTERN;
+  struct tr_pattern rep = STATIC_TR_PATTERN;
   char *s;
   mrb_int len;
   mrb_int i;
   mrb_int j;
   mrb_bool flag_changed = FALSE;
   mrb_int lastch = -1;
-  struct tr_pattern *rep;
 
   mrb_str_modify(mrb, mrb_str_ptr(str));
-  tr_parse_pattern(mrb, &pat, p1, TRUE);
-  rep = tr_parse_pattern(mrb, &rep_storage, p2, FALSE);
+  tr_parse_pattern(mrb, &pat, p1, TRUE, NULL);
+  tr_parse_pattern(mrb, &rep, p2, FALSE, &pat);
   s = RSTRING_PTR(str);
   len = RSTRING_LEN(str);
 
@@ -503,11 +504,7 @@ str_tr(mrb_state *mrb, mrb_value str, mrb_value p1, mrb_value p2, mrb_bool squee
     if (i>j) s[j] = s[i];
     if (n >= 0) {
       flag_changed = TRUE;
-      if (rep == NULL) {
-        j--;
-      }
-      else {
-        mrb_int c = tr_get_character(rep, RSTRING_PTR(p2), n);
+      mrb_int c = tr_get_character(&rep, RSTRING_PTR(p2), n);
 
       if (c < 0 || (squeeze && c == lastch)) {
         j--;
@@ -515,17 +512,16 @@ str_tr(mrb_state *mrb, mrb_value str, mrb_value p1, mrb_value p2, mrb_bool squee
       }
       if (c > 0x80) {
         tr_free_pattern(mrb, &pat);
-          tr_free_pattern(mrb, rep);
+        tr_free_pattern(mrb, &rep);
         mrb_raisef(mrb, E_ARGUMENT_ERROR, "character (%i) out of range", c);
       }
       lastch = c;
       s[i] = (char)c;
     }
   }
-  }
 
   tr_free_pattern(mrb, &pat);
-  tr_free_pattern(mrb, rep);
+  tr_free_pattern(mrb, &rep);
 
   if (flag_changed) {
     RSTR_SET_LEN(RSTRING(str), j);
@@ -658,7 +654,7 @@ str_squeeze(mrb_state *mrb, mrb_value str, mrb_value v_pat)
 
   mrb_str_modify(mrb, mrb_str_ptr(str));
   if (!mrb_nil_p(v_pat)) {
-    pat = tr_parse_pattern(mrb, &pat_storage, v_pat, TRUE);
+    pat = tr_parse_pattern(mrb, &pat_storage, v_pat, TRUE, NULL);
     tr_compile_pattern(pat, v_pat, bitmap);
     tr_free_pattern(mrb, pat);
   }
@@ -749,7 +745,7 @@ str_delete(mrb_state *mrb, mrb_value str, mrb_value v_pat)
   uint8_t bitmap[32];
 
   mrb_str_modify(mrb, mrb_str_ptr(str));
-  tr_parse_pattern(mrb, &pat, v_pat, TRUE);
+  tr_parse_pattern(mrb, &pat, v_pat, TRUE, NULL);
   tr_compile_pattern(&pat, v_pat, bitmap);
   tr_free_pattern(mrb, &pat);
 
@@ -817,7 +813,7 @@ mrb_str_count(mrb_state *mrb, mrb_value str)
   uint8_t bitmap[32];
 
   mrb_get_args(mrb, "S", &v_pat);
-  tr_parse_pattern(mrb, &pat, v_pat, TRUE);
+  tr_parse_pattern(mrb, &pat, v_pat, TRUE, NULL);
   tr_compile_pattern(&pat, v_pat, bitmap);
   tr_free_pattern(mrb, &pat);